"Intelligent Updater session complete.All updates failed to install on the machine. For more details about the processing, please check the log file "Log.IntelligentUpdater.txt" created in the user's temporary directory."

I was thinking of this and there might be a way for you to schedule a task (Accessories - System Tools - Task Scheduler) to run Live Updater with an Administrator account login to do the updates on the system. I have never tried it since the systems I manage have to be manually updated since they aren't connected to the Internet and do require an admin to do. If your systems aren't connected where Live Update can run, then the daily changing of the definitions file name will prevent this from working unless task schduler can use an * in the file name to be run. Never have tried that. Good Luck.

It used to be that if you manually ran LiveUpdate (clicked the button in the interface), it's running as the currently logged in user, but scheduled LiveUpdate ran as System. I have not seen anything to suggest that this is different with LiveUpdate Engine (LUE), which replaced the old Windows LiveUpdate from 11.x and earlier.

Short version: the scheduled LiveUpdate should work regardless of your users' rights.